The New York Times, January 13, 1920. The Times offered a retraction on July 17, 1969, as Apollo 11 was on its way to the moon.

To place a man in a multi-stage rocket and project him into the controlling gravitational field of the moon where the passengers can make scientific observations, perhaps land alive, and then return to earth—all that constitutes a wild dream worthy of Jules Verne. I am bold enough to say that such a man-made voyage will never occur regardless of all future advances.

What can be more palpably absurd than the prospect held out of locomotives traveling twice as fast as stagecoaches?

The Quarterly Review, March, 1825.

Hence, if it requires, say, a thousand years to fit for easy flight a bird which started with rudimentary wings, or ten thousand for one which started with no wings at all and had to sprout them ab initio, it might be assumed that the flying machine which will really fly might be evolved by the combined and continuous efforts of mathematicians and mechanicians in from one million to ten million years--provided, of course, we can meanwhile eliminate such little drawbacks and embarrassments as the existing relation between weight and strength in inorganic materials. [Emphasis added.]

The New York Times, Oct 9, 1903, p. 6.

That the automobile has practically reached the limit of its development is suggested by the fact that during the past year no improvements of a radical nature have been introduced.

Ken Olson, president, chairman and founder of Digital Equipment Corporation (DEC), in a talk given to a 1977 World Future Society meeting in Boston. This is widely quoted but Olsen claims it is taken out of context, that he was not referring to personal computers but to a household computer that would control the home.
Reference: "Ken Olsen", Snopes, includes bibliography.

Television? The word is half Latin and half Greek. No good can come of it.

Well-informed people know that it is impossible to transmit the human voice over wires as may be done with dots and dashes of Morse code, and that, were it possible to do so, the thing would be of no practical value.

The more important fundamental laws and facts of physical science have all been discovered, and these are so firmly established that the possibility of their ever being supplanted in consequence of new discoveries is exceedingly remote. Nevertheless, it has been found that there are apparent exceptions to most of these laws, and this is particularly true when the observations are pushed to a limit, i.e., whenever the circumstances of experiment are such that extreme cases can be examined. Such examination almost surely leads, not to the overthrow of the law, but to the discovery of other facts and laws whose action produces the apparent exceptions.

Albert Abraham Michelson, Light waves and their uses, University of Chicago Press, 1903. The first sentence is often quoted out of context, completely misrepresenting his intent.

Every attempt to refer chemical questions to mathematical doctrines must be considered, now and always, profoundly irrational, as being contrary to the nature of the phenomena. . . . but if the employment of mathematical analysis should ever become so preponderant in chemistry (an aberration which is happily almost impossible) it would occasion vast and rapid retrogradation....

Although most commonly attributed to him, (it has also been attributed to anonymous US Patent Office employees of varying dates, as well as British ones), there is no evidence that Duell ever held this opinion, let alone stated it. [1]